Inspired by puffer fish, research designs new bionic skin

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Skin is a mechanism of self-protection for humans and animals. In biological systems, soft tissue can effectively adjust mechanical strength through strain enhancement to avoid injury. As a system that enables robots to have a real touch, electronic skin greatly improves the flexibility and ductility of robots, but it cannot sense pain and avoid danger like human skin.

Recently, researchers from Ningbo Institute of Materials, Chinese Academy of Sciences were inspired by the three-dimensional deformation of puffer fish skin, and based on their accumulation of research on the construction of carbon-based/polymer composite films and their flexible actuation and sensing, they proposed a strain sensing enhancement (SPS) effect. 's bionic skin realizes the transition from touch to pain perception.

Traditional electronic skins are usually built on a single pressure-sensing mode. Although they can sense pressure, problems will occur when a certain pressure threshold is exceeded. In a sense, these skins are like switches that record pressure, but you can't really feel how much pressure you're under. In addition, these skins are easily damaged because beyond a certain pressure limit there is a lack of sensitivity.

The bionic skin newly developed by researchers at the Chinese Academy of Sciences combines the body's somatosensory system to achieve a controllable threshold transition from touch to pain when tissue or skin is stretched. Specifically, the researchers employed interfacial self-assembly and in-situ functionalization strategies to construct two-dimensional graphene-based elastic ultrathin films (ECFs) with interfacial interlocking structures, which have similar perception to real vertebrate neurosensory systems. trend.

In ECF, the dynamic network formed by the stacking of graphene sheets can sensitively respond to external strain stimuli through different degrees of slippage. Furthermore, by adjusting the thickness of the graphene sheets, the strain threshold can be varied in the range of 7.2% to 95.3%.

In addition, inspired by the three-dimensional deformation of the puffer fish skin, the researchers integrated ECF into a self-supporting form of bionic skin, which can not only monitor the three-dimensional aerodynamic deformation in real time, but also effectively detect the three-dimensional deformation in an over-expanded state through the SPS effect. Dynamic pain perception.

The research has significant implications for the robotics field. After the robot has perception, it can autonomously avoid danger and prolong its service life. In the future, knowing cold and warm and feeling pain may no longer be exclusive to humans and animals.